Oil painting stretchers



1966 s. KUPERSMITH OIL PAINTING STRETCHERS Filed Oct. '7, 1964 FIG.3

INVENTOR, Sum Kupersmiih,

ATTORNEY.

United States Patent 1 3,291,196 OIL PAINTING STRETCHERS Sam Kupersmith, 5305 Avenue D, New York, N.Y. Filed Oct. 7, 1964, Ser. No. 402,167 6 Claims. (Cl. 160-374.1)

The present invention relates to oil painting stretchers of the type comprising expandable frames on which the margins of a canvas is secured.

An object of this invention is to provide a novel and improved oil painting stretcher which is a frame though made of *adjustably joined bars of rectangular cross section', will be only in perinietrical line contact with the canvas; said frame being forwardly flared to accomplish this. Another object is to provide a novel and improved stretcher of the character described, in which the frame parts are joined by adjustable cleats offering wedge means to shift adjacent frame bars apart.

A further object thereof is to provide a stretcher of the kind set forth, having a strengthening cross bar joined to opposite frame parts by adjustable cleats which are suitable for the flared structureand yet maintain the cross bar in the general plane of the frame.

Still a further object of this invention is to provide novel and improved stretcher constructions in which all the frame parts, and a cross bar if included, are of rectangular cross section, associated by cleats which automatically position all the parts as required, and which stretcher is simple in construction, reasonable in cost, easy to adjust and efficient in carrying out the purposes for which it is designed.

Other objects and advantages will become apparent as this disclosure proceeds.

For one practice of this invention, four wooden bars whose ends are mitered, are positioned to form a rectangular frame; opposite frame parts being identical. On the back of this frame formation, adjacent parts are joined by a cleat which overlaps them and includes a wedge enterable between them; the taper of such wedge being towards the outer perimeter of the frame. There is of course, one such cleat for each juncture of the frame. The cleat is essentially a shallow, wide V-channel; said wedge being along the apex line of said channel, in symmetry therewith and across the inner periphery of the frame; the apex of the wedge being near mid-length of the channel. Each wall of the channel has a lengthwise slot running substantially parallel to the adjacent face of the wedge. A screw through each slot, maintains the assembly. The cleat structure for joining a cross bar end to a frame bar, has its wedge component to one side of the apex line of the channel as will be explained. These cleats are also adaptable for frames which are other than rectangular.

It is of importance to note that all bars constituting the frame structure are of rectangular cross section and that when the canvas is mounted thereon, there will only be a perimetrical line contact around the spanned front part of the canvas. To accomplish this heretofore, the perimetrical frame bars had to be of trapezoidal cross section. The necessary labor and increased cost which this entailed, is entirely avoided by the present invention.

In the accompanying drawing forming part of this s ecification, similar characters of reference indicate corresponding parts in all the views.

FIG. 1 is a rear view of a stretcher construction embodying the teachings of this invention. The rectangular frame, which is the shape most used and here shown, comprises four wooden bars of rectangular cross section; the ends of said bars being mitered and adjacent ends being joined by a cleat. Also shown in this embodiment is a central cross bar and the cleats joining its ends to a pair of opposite frame bars.

FIG. 2 is a section taken at line 2-2 in FIG. 1, including a canvas mounted thereon.

All of the following figures are enlarged.

FIG. 3 is a fragmentary rear view of the stretcher.

FIG. 4 is a perspective view of a cleat for a corner juncture of the frame.

FIG. 5 is an end View of FIG. 4.

FIG. 6 is a bottom perspective view of FIG. 4.

FIG. 7 is a perspective view of a cleat for the juncture of an end of the cross bar with the frame.

FIG. 8 is a bottom perspective view of FIG. 7;

In the drawing, the stretcher for the canvas 15, is a rectangular frame designated generally by the numeral 16, comprising four wooden bars 17, 18, 19, 20 of rectangular cross section whose ends are mitered. All said bars are cut from the same stock from which a squareended cross bar 21 may also be had, if a strengthening means is to be included. Adjacent ends of the frame bars, are joined by a cleat indicated generally by the numeral 22; there being one such cleat at each of the frame corners. The cleats denoted generally by the numeral 23, are used to join the ends of the cross bar 21, to the opposite frame bars 18 and 20.

The cleat 22 is a V-channel, the inner surfaces 24, 25 of whose walls, are in obtuse angled relation. The rear faces of adjacent ends of the frame bars, rest on said inner surfaces 24, 25 respectively. A symmetrically positioned wedge indicated generally by the numeral 26, extends within the channel between the channel walls, from one end of said channel and part way along the length of said channel; the faces 27, 28 of said wedge, diverging towards said channel end; the face 27 being opposite the surface 24 while the face 28 is opposite the surface 25. Said cleat 22 may be a one-piece casting offering an anvil 29 as an extension out of the channel. The channel wall 30 has an elongated slot 31 along the face 27 of the wedge and the channel wall 32 has an elongated slot 33 along the face 28; said slots, of course being in converging relation towards the other end of the channel. Headed screws 34, 35 through said slots, maintain the assembly. The general scheme of construction of the cleat 23 is like that of the cleat 22, except that the wedge 36 thereof is to one side of, and one face of said wedge has in its plane the apex line 37 of the channel 38. In the cleat 22, its wedge 26 is symmetrical with respect to the apex line 40. In the cleat 23, the slot 41 is along the face 39 and the slot 42 is along the face 43; said wedge 36 being between said slots. The angle of the channel of the cleat 23 is greater than the angle of the channel of the cleat 22 by an amount equal to half the difference between 180 degrees and the angle of the channel of the cleat 22. For a practical embodiment, it is suggested that the angle of the channel of the cleat 22 shall be degrees and that of the channel of the cleat 23 shall be degrees.

Making the channel walls of uniform thickness, the lines 44 and 45 on the respective cleats, serve as guides for the assembly of the frame 16 in the first instance, before mounting the canvas 15 by wrapping the latters marginal edges around the outer perimeter of the frame and securing it by tacks 46. It is evident that the margin of the front of the canvas will be in line contact with the frame body. The size of the frame will determine whether the cross bar 21 should be included, to strengthen it.

Upon assembly, all the cleats are positioned so that their wedges are slightly entered between adjacent frame parts. Then upon loosening the screws at one cleat at a time, it is forced by hammer blows to shift whereby the wedge thereof shall further be entered, whereupon 3 the screws are again tightened. This makes the canvas 15 taut.

This invention is capable of numerous forms and various applications without departing from the assential features herein disclosed. It is therefore intended and desired that the embodiment shown herein shall be deemed illustrative and not restrictive and that the patent shall cover all patentable novelty herein set forth; reference being had to the following claims rather than to the specific showing and description herein to indicate the scope of this invention.

I claim:

1. In an oil painting stretcher of the character described, thecombination with a frame comprising bars of rectangular cross section, a cleat overlapping the back surfaces of two of said bars which are adjacent each other, said cleat comprising a V-channel; the inner surfaces of the walls of said channel, being in obtuse angled relation; each of said channel surfaces contacting one of said overlapped frame bars respectively and a wedge within said channel and extending along the line of intersection of the planes of said channel wall surfaces, adapted to be entered between said two frame bars by movement of said cleat whereby said two frame bars are shifted apart; each of said channel walls having a lengthwise slot therethrough along the converging surfaces of said wedge respectively; said wedge being positioned between said slots and a screw in each of said slots respectively, releasably securing said cleat to said two frame members whereby said two bars are in surface contact with the walls of said channel respectively; the direction of convergence of the converging walls of said wedge, being along said channel.

2. The combination as defined in claim 1, wherein said wedge is symmetrically positioned with respect to said line of intersection. a

3. The combination as defined in claim 1, wherein said wedge is positioned at, along and only to one side of said line of intersection.

4. A cleat for adjustably joining two adjacent frame bars of an oil painting stretcher structure, comprising a V-channel, the inner surfaces of whose walls are in obtuse angled relation and a wedge within the channel and extending along the line of intersection of the planes of said channel wall surfaces; each of said channel walls having a lengthwise slot therethrough along the converging surfaces of said wedge respectively; said wedge being positioned between said slots; the direction of convergence of the converging surfaces of said wedge, being along said channel.

5. The cleat as defined in claim 4, wherein said wedge is symmetrically positioned with respect to said line of intersection. I

6. The cleat as defined in claim 4, wherein said wedge is positioned at, along and only to one side of said line of intersection.

' References Cited by the Examiner UNITED STATES PATENTS 192,319 6/1877 Witt l--374.1 272,162 2/1883 Shattuck -3741 320,300 6/1885 Shattuck 160374.1 335,480 2/1886 Rawbone 160374.1

HARRISON R. MOSELEY, Primary Examiner.

P. C. KANNAN, Assistant Examiner. 

1. IN AN OIL PAINTING STRETCHER OF THE CHARACTER DESCRIBED, THE COMBINATION WITH A FRAME COMPRISING BARS OF RECTANGULAR CROSS SECTION, A CLEAT OVERLAPPING THE BACK SURFACES OF TWO OF SAID BARS WHICH ARE ADJACENT EACH OTHER, SAID CLEAT COMPRISING A V-CHANNEL; THE INNER SURFACES OF THE WALLS OF SAID CHANNEL, BEING IN OBTUSE ANGLED RELATION; EACH OF SAID CHANNEL SURFACES CONTACTING ONE OF SAID OVERLAPPED FRAME BARS RESPECTIVELY ANDA A WEDGE WITHIN SAID CHANNEL AND EXTENDING ALONG THE LINE OF INTERSECTION OF THE PLANES OF SAID CHANNEL WALL SURFACES, ADAPTED TO BE ENTERED BETWEEN SAID TWO FRAME BARS BY MOVEMENT OF SAID CLEAT WHEREBY SAID TWO FRAME BARS ARE SHIFTED APART; EACH OF SAID CHANNEL WALLS HAVING A LENGTHWISE SLOT THERETHROUGH ALONG THE CONVERGING SURFACES OF SAID WEDGE RESPECTIVELY; SAID WEDGE BEING POSITIONED BETWEEN SAID SLOTS AND A SCREW IN EACH OF SAID SLOTS RESPECTIVELY, RELEASABLY SECURING SAID CLEAT TO SAID TWO FRAME MEMBERS WHEREBY SAID TWO BARS ARE IN SURFACE CONTACT WITH THE WALLS OF SAID CHANNEL RESPECTIVELY; THE DIRECTION OF CONVERGENCE OF THE CONVERGING WALLS OF SAID WEDGE, BEING ALONG SAID CHANNEL. 